The extraction of features from the images for training and testing was made using a Deep
Convolutional Network: VGG Face [1]}.
The network has 21 layers (18 for convolution and pooling and 3 for classification, respectively) plus a Softmax function at the end for prediction purposes.
VGG is pre-trained on a celebrity database that contained 2.6 million images of 2,622 individual identities.
Aiming only feature extraction, the Softmax function is removed, and the resulting feature vector for every image has 2,622 dimensions.
